How Did Europeans' Impact on Native Americans Affect Their Relations

How did Europeans' impact on Native Americans affect their relations with Africans in the sixteenth century?

A) The success of the effort to convert Native Americans in large numbers prompted them to attempt the same thing in Africa.
B) The near eradication of Native populations from European disease contributed to the decision to import African slaves to work on sugar plantations in the Americas.
C) After dealing with indigenous people's hostility, the Spanish and Portuguese believed Africans would be tractable and easier to manage.
D) Europeans learned that converting Indians was too difficult, so they imported West Africans who were already Catholic.